The simplest backup script for personal uses, feel free to modify.

backup.ps1

# WARNINGS AND WORKINGS:
# The script can be downloaded anywhere, but if there is no folder named as defined in $backupFolder, then it will create it.
# BEFORE running the script, add the folders to backup in the $folders array.
# To execute backup.ps1, calling it from a PowerShell session is enough (.\backup.ps1).

# Useful variables to modify and/or use.
$backupFolder = ".\backup"
$desktop = [Environment]::GetFolderPath("Desktop")
$folders = @()

# File matching, feel free to add or modify.
$files = foreach($folder in $folders) {
    (Get-ChildItem "$folder/*.json").FullName
}

if(-not (Test-Path $backupFolder)) {
    New-Item -ItemType Directory -Path $backupFolder
}

foreach($file in $files) {
    $itemName = (Get-Item $file).Name

    Copy-Item -Path $file -Destination "$backupFolder\$itemName"
}